Use groundtruth from testing directory

unittest/apiexample_test.cc

@@ -25,7 +25,7 @@ TEST(TesseractTest, ApiExample)
 {
     char *outText;
     std::locale loc("en_US.UTF-8"); // You can also use "" for the default system locale
-    std::ifstream file("testfiles/phototest.txt");
+    std::ifstream file("../testing/phototest.txt");
     file.imbue(loc); // Use it for file input
     std::string gtText((std::istreambuf_iterator<char>(file)),
              std::istreambuf_iterator<char>());